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And, the battery may be perfectly fine… but then again, it may not. It is certainly a suspect. A load test is certainly a good next step, and can be done for free. I like free things… A battery that won’t charge properly puts an excessive strain on the alternator that it was never designed to handle and will quickly cause it to fail. A good battery should never drop below 10 volts when cranking, assuming the starter is in good shape and not pulling excessive current.
[quote=”carsgovroom” post=131064] I want the evidence, you know? Also, I need to hone these skills, so it’s a good idea for me to go through the paces. Learn by doing, right?[/quote]
Exactly.btw, I edited my previous comment, please check it.
It has a schrader valve. EDIT: maybe… I just remembered that some years of this engine did not have a schrader valve and you have to use a T-fitting in the line. You should consult your service manual to be sure.
As the RPM increases, the vacuum decreases, so the leak ‘gets smaller’ and could even become invisible to the engine, at which case the fuel trims would normalize. This should be seen instantaneously in STFT. At deceleration the opposite happens.
If the fuel trims remain over 10% with close to zero engine vacuum, it is probably not a vacuum leak and instead a fuel delivery problem. In the case of a dirty/bad injector, the computer is increasing fuel trim so that the other injectors compensate. It usually won’t throw a code until it is unable to compensate.
Yes, sensor nomenclature can be fun. Especially on cars that have both cam and crank sensors, because both could be called TDC depending on perspective. I prefer to reference them as crank or cam sensors, to eliminate any ambiguity. Technically speaking, the term ‘top dead center’ refers to the position of a piston in the cylinder, and that is determined by the crankshaft. For timing purposes, though, TDC occurs twice, at the end of compression stroke, and end of exhaust stroke. Depending on what the needs of the computer are seems to determine the names of the sensors it uses.
Either air has gotten into the system or the master cylinder is failing. If the air bleed doesn’t have an effect, I would be looking at the master cylinder next. If the air bleed does fix it, then you need to find out how and why the air got in there.
Cautions always apply. Plus, other people read these forum posts and apply the advice given to their own situation. No harm in providing as much information as possible.
Does your manual elaborate on the ‘pulses’ as in frequency or modulation of them? I do not know the inner workings of your particular igniter, but some utilize timing circuits and are looking for those pulses to be of a specific duration. Out of range pulses are ignored to protect the igniter. If it is a simple transistor switch, all of the timing of the pulses may be done by the ECM. I do not have that level of technical knowledge about your vehicle. I suppose you can try your improvised testing method, I wouldn’t be able to stop you from doing so anyway. It would seem to me, though, that if what you propose is a viable testing method then it would be outlined in the service manual, especially since it is seemingly simple. There may be a reason why it isn’t there. That unknown reason is why I provided all of the caution.
Generally, when fuel trims are that high a positive number, there is a fuel delivery issue. Vacuum leaks can cause a rise in LTFT, but unless it is severe, won’t raise it that high. Have you checked the fuel pressure? You may be experiencing a weak fuel pressure regulator. If fuel pressure is ok, perhaps a dirty/bad injector is the culprit.
The TDC sensor goes by several names, including crankshaft angle sensor and crankshaft position sensor. The computer uses this sensor to determine where the crankshaft is for engine timing and other management tasks. It is not the same as a camshaft sensor. TDC means “top dead center” and refers to the position of the crankshaft. It is common that these get contaminated with oil and dirt without actually failing. I would first remove, clean, and reinstall the existing sensor before replacement. Many good sensors have been thrown in the trash due to poor diagnostic practices. That isn’t to say that yours didn’t actually fail. However, I always like to KNOW I need it before I swap it, whatever ‘it’ may happen to be. Saves lots of dollars, too.
As for the ELD, it could have been an intermittent fault. It can sometimes be caused by a wiring problem in the harness rubbing on the intake manifold. Check your fuses and wiring. Clear the computer, and see if it comes back.
How old is the battery? Have you had it load tested? A bad battery can definitely damage the alternator.
[quote=”mscherst” post=131020]As I’m looking through the manual, I think I can devise a test of the ICM that I’m surprised I haven’t seen online yet. Page 11-72 (terminal 13) shows that the ECM sends 12V to the ICM when the ignition is ON, and pulses when engine is running. So if I manually provide 12V to the ICM, and it does ground the coil, than I have confirmed that the ICM is not getting a signal from the ECM, correct? Granted, this doesn’t completely test the ICM, but at least part of it.[/quote]
Depending on how the electronics for the igniter were designed, applying 12v directly may not do what you think. In digitally controlled circuits, many are edge based. Meaning, the 12v being applied may not itself be the trigger, but rather 12v being applied and then removed in a prescribed period of time. A pulse of a certain width. Example, 12v being applied for 10ms and then removed. It is the falling edge that is the actual trigger, not just 12v being applied. Additionally, circuits can use the rising edge instead of the falling edge.Also note that many digital circuits use 5v signal/feedback lines, and applying 12v to these parts of the circuit can instantly damage them, frying a formerly good (and potentially expensive) component.
Eric was using a power probe, different than a continuity tester, although the power probe can be used for that purpose. It is a handy tool. I don’t have one, yet…
The coil in nearly all newer cars (I don’t say ALL, because I do not like speaking in absolutes) is ground-side switched. The continuity tester should light (or ohmmeter showing 0.00 or damn close) when there is a path to ground through the igniter. When the igniter switches, the path is broken, so the light goes away (or the ohmmeter shows infinity–or some random high resistance if the switching is faster than the refresh on the meter). An ammeter could also be used for this, showing current to ground when the circuit is closed, and no current when the circuit is switched open, and this would work on both positive and negative sides of the primary. The basic idea is the same; we want to see that some control is happening on the coil (pulsing of the power to the primary side of the coil) to cause secondary discharge.
Your bank 1 O2 sensor 2 has a heater circuit fault, improper resistance. This is the driver’s side downstream (past the catalytic converter) sensor. That does not mean the sensor is bad. First, check all wiring. Melted/damaged wires (and connectors!) have caused many perfectly good sensors to be replaced unnecessarily. If the wiring is good, the sensor may still be functioning ok, but the heater has gone bad. The O2 sensor needs to be about 600 degrees before it works right, so the heater helps the O2 sensor work before the exhaust system has fully warmed up.
The way the spark is produced is by the igniter (aka ignition module, ICM, etc) switching the ground on and off to the coil primary. The igniter takes the place of the points and condenser on the non-electronic ignition systems. When the ground switches off, the electromagnetic field inside the coil collapses and causes the spark discharge on the coil secondary. This relies on 12v being constantly supplied to the coil when the key is on, and the electronics doing their work on the ground switching.
Do a ‘confidence test’ on the coil. With a voltmeter and the key on, check for the constant 12 volts on the + terminal of the coil’s primary. If you do not have 12v there, you need to stop and find out why before doing anything else. If you have 12v on the coil, now you need to see if the coil has an open or shorted winding. Disconnect all wires to the coil. Using an ohmmeter on its lowest range, check between the + and – terminals on the coil. You should get a very small resistance, usually between 0.4 and 2 ohms. If you have no resistance, it is shorted. If you get infinite resistance, it is opened. If you get the expected resistance, test the secondary. Set the ohmmeter to a higher range and with one of the leads on the primary + terminal, put the other lead where the spark discharges. You should usually read between 6k and 15k ohms. If you get no resistance, infinite resistance, or an unusually low or high resistance, the coil should be replaced. If all is well, then the coil is good.
Ok, so you have done the ‘confidence test’ on the coil, now you need to check if the coil is being switched on and off. A continuity tester or ohmmeter can be used for this. Disconnect the wire at the – side of the coil primary. Connect one side of the tester to a known good ground, and the other side of the tester to the disconnected wire. Now, you or a helper, crank the engine. The tester should show the continuity to ground being switched on and off as the engine turns. If it does, your igniter is good. If the tester stays off or is lit constantly, the igniter is bad.
If the coil and igniter are both good, your problem lies elsewhere.
The oil to the rocker arm shafts is provided by pressure created by the camshaft bearings. The camshaft bearings have holes in them that allows the oil to move to the rockers. If the cam bearings have spun a little, the holes could be blocked. Or, the cam bearings are so worn that they are incapable of moving oil to the rockers due to the clearances being too wide.
Of course.. http://www.ericthecarguy.com/83-videos/the-basics/1015-how-to-perform-a-compression-test
The service manual for your vehicle also describes the procedure and what the specifications for proper readings are.